Researchers in a pilot project involving the city’s Department of Health and Mental Hygiene, Columbia University and Yelp trawled the website for reviews that included words like “sick,” “vomit,” “diarrhea” and “food poisoning” between July 2012 and March 2013.

Roughly 294,000 Yelp reviews were analyzed, and researchers found 468 posts that were consistent with cases of recent food-borne illnesses.

Only 15 of those cases had been independently reported to the Health Department.

“The results suggest that online restaurant reviews might help to identify unreported outbreaks of food-borne illness and restaurants with deficiencies in food handling,” researchers wrote in the US Centers for Disease Control and Prevention’s Morbidity and Mortality Weekly Report on Thursday.

Further review of those nearly 500 cases led the department to launch three investigations into restaurant-related food-poisoning outbreaks.

The department found that 16 people were sickened by dishes such as shrimp and lobster cannelloni and macaroni and cheese spring rolls due to improper cold-food storage, bare-hand contact with the food and live roaches.

The report noted, however, that the analysis was limited because it required considerable time and resources reading reviews, sending emails and conducting interviews.

Researchers also needed to make contact with reviewers, and more than 100 refused requests for follow-up interviews.

“As social-media usage continues to grow among US adults, health departments might consider additional surveillance methods to capture illness reports from those more likely to post a restaurant review online than contact a health department,” the researchers wrote.

The New York City Health Department plans to continue refining and improving the project, the report added.